Pacific Reef Assessment and Monitoring Program: Sightings of marine species of interest during towed-diver surveys of the U.S. Pacific reefs from 2000-09-16 to 2017-06-20 (NCEI Accession 0189253)

The presence data described here include "off transect" sightings of marine species of interest observed during fish towed-diver surveys conducted by the Pacific Islands Fisheries Science Center (PIFSC) Ecosystem Sciences Division (ESD)--formerly the Coral Reef Ecosystem Division--as part of the Pacific Reef Assessment and Monitoring Program (Pacific RAMP). These underwater surveys were conducted across coral reef habitats of the Hawaiian and Mariana Archipelagos, American Samoa, and the Pacific Remote Island Areas from 2000 to 2017. Presence data for marine species observed outside the fish towed-diver's transect were recorded, including the taxon name - generally to species level, the number observed, and in most cases the size in centimeters. Marine species observed include sea turtles, dolphins, eels, rays, seals, as well as a number of fish species that were considered to be species of interest, such as the humphead wrasse, bumphead parrotfish, most reef sharks, and species of large grouper. While not included in this dataset, the towed-diver method was primarily used by ESD to survey large-bodied (>50 cm) fishes within the towed-diver transect and to assess the reef habitat. This dataset also includes fish species of interest observed inside the transect area, but only where those were less than 50 cm in total length (and therefore not recorded with the large-bodied fish towed-diver survey data).

Generally, the towed-diver method involves towing a pair of SCUBA divers--one benthic and one fish--behind a small boat for 50 minutes, approximately following the ~15-m depth contour and covering a linear distance of about 2 kilometers per survey. Each diver was equipped with a towboard and attempted to maintain position ~1 meter above the surface of the reef for the duration of the survey. A complete towed-diver survey includes ten 5-minute segments, with visual observations recorded by 5-minute segment. Sightings of marine species included in this dataset were also recorded by the 5-min segment in which the species was observed.